The only reason I want an adventurer's guide for dungeon, trial, and raid bosses is that I want to learn about the lore behind them, just as I enjoyed learning about WoW's bosses from the journal. Even after years of playing this game, a lot of bosses I encounter feel either filler or random without much to know about them if there's anything to begin with. Here's a list of just an example of bosses I'm curious about:

- The majority of Alexander bosses (From A1 to A11)
- E1 & E7 bosses
- The Dark elf boss in the most recent dungeon (The only thing you can know about him is that he guards the place, but why is he called a Dark elf? What's an elf from his perspective?)
- All three boses of the Aetherfont
- Cereberus and Angra Mainyu (Come on, there has to be something about them)

Of course, there's way more, and I realize some of these have lore drops in the Enclyopedias, but I prefer to learn about them in-game rather than external sources.